The Only 4 Exercises You Really Need

I do my best to exercise 5 to 6 times a week, but there are days when I simply cannot pull myself out of bed in time to sweat before work, or when I'm traveling and my normal routine is completely thrown off track. Instead of completely scrapping my routine, I’ll try and squeeze in a few bodyweight exercises—namely squats, planks, chair dips and pushups.

Must-Do Move #1: Chair Dips

Great for toning your triceps and core

Sit on the edge of a sturdy, stable chair with legs together, knees bent and feet flat on floor a few feet in front of chair. Place your hands about six inches apart, and firmly grip the edges of the chair. Slide your butt just off the front of the chair so that your upper body is pointing straight down. Keep your abdominals pulled in and your head centered between your shoulders. Bend your elbows and lower your body in a straight line. When your upper arms are parallel to the floor, push yourself back up, being careful not to lock elbows. Repeat. (Want more arms? Here's how to Tone Your Arms—In 10 Minutes!)

Make it easier: Keep feet close to the chair and the dip slow, controlled, and shallow.

Add a challenge: If you’re intermediate, position feet a little farther from chair, and deepen your dip. If you’re advanced, straighten your legs completely, and place heels on floor, or place one or both feet on another chair, bench or exercise ball. Perform deep but controlled dips.

MORE: 5 Moves That Seriously Lift Your Butt

Must-Do Move #2: Push-ups

Great for toning your chest, shoulders, triceps, back, hips, and abs

Start in a basic push-up position with hands directly beneath shoulders and body in a straight line. Bend elbows out to sides and lower body almost to floor (or as far as you can). Keep abs tight and body in a line. Hold for 1 second, then push back up. Repeat. (Want to get stronger? Boost your stamina and reset your fat-loss hormones using Rodale's The Hormone Fix.)

Make it easier: If you’re a beginner, do push-ups on knees. Keep the movement shallow and controlled. Still too challenging? Start with a push-up on the wall, progressing to the floor as you become stronger.

Add a challenge: If you’re advanced, try lifting one leg off the floor as you do each push-up. (Need a visual? Watch how to Master Push-Ups at Any Level.)

Must-Do Move #3: Squats

Great for toning your glutes, hamstrings and quads

Stand with feet parallel and hip-width apart. Bend your knees and lower your body into a squat position, as if you are sitting back into an imaginary chair, keeping knees behind toes. Stop when your knees are at 90 degrees. Slowly press through your heels and squeeze your glutes as you return to standing.

Make it easier: Don’t bend knees as deeply

Add a challenge: Add weights, do a single-legged squat, or perform squats on an unstable surface, like a balance disc or Bosu ball. To incorporate cardio, do squat jumps.

Must-Do Move #4: Plank

Great for toning your abs, back, chest, forearms and shoulders

To come into plank pose, hold a push-up position, weight on balls of feet and hands, wrists directly below shoulders, arms straight, and body in line from head to heels. Hold for as long as you can, working up to 1 minute. That’s 1 rep. Do 2 or 3 reps.

Make it easier: Instead of being on hands, lower yourself to your forearms.

Add a challenge: Raise 1 leg off the floor and hold for 30 seconds. Switch legs and hold for another 30 seconds to complete 1 rep. To add variety, try side plank: Lie on your right side with your legs straight, and feet stacked, right hand directly under right shoulder. Lift hips off floor and raise left arm to sky, keeping left hand directly over left shoulder. Hold for 30 to 60 seconds. Switch sides and repeat to complete 1 rep.